I have read about laying multiples and I understand how to do it. I want to create a spreadsheet for helping to do so in case bookies
1) offer bonus to winnings or
2) refund if only one of the legs lose.
For 1), I know it is easy to just lay as if the bonus not exists and profit if all my legs win. But I want to get profit no matter win or lose. So I want to get a spreadsheet that helps me to calculate how much the odds of each leg is improved on average by the final bonus offered to winning all the legs.
For 2), I think it is pretty complicated to account for all cases if the mutliple contains more than 3 legs. So I would like to concentrate on the 2nd last leg as if it a refund only for the 2nd last leg. How to calculate how much the odds of each leg before it and itself is improved due to the bonus? And how to take into account the last leg?
If someone can help me with the formula, I would create it and share it with everyone here. Many thanks.